diff --git a/src/lib.rs b/src/lib.rs
index 5f8715c1..9436c358 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -82,7 +82,6 @@ Feel free to add your project to this list if you happen to use **nalgebra**!
 #![deny(unused_qualifications)]
 #![deny(unused_results)]
 #![warn(missing_docs)]
-#![feature(core)]
 #![cfg_attr(test, feature(test))]
 #![doc(html_root_url = "http://nalgebra.org/doc")]
 
diff --git a/src/structs/ortho.rs b/src/structs/ortho.rs
index 19b38e84..39a15181 100644
--- a/src/structs/ortho.rs
+++ b/src/structs/ortho.rs
@@ -1,5 +1,4 @@
-use std::num;
-use traits::structure::BaseFloat;
+use traits::structure::{BaseFloat, Cast};
 use structs::{Pnt3, Vec3, Mat4};
 
 #[cfg(feature="arbitrary")]
@@ -162,13 +161,13 @@ impl<N: BaseFloat> OrthoMat3<N> {
     /// The width of the view cuboid.
     #[inline]
     pub fn width(&self) -> N {
-        num::cast::<f64, N>(2.0).unwrap() / self.mat.m11
+        <N as Cast<f64>>::from(2.0) / self.mat.m11
     }
 
     /// The height of the view cuboid.
     #[inline]
     pub fn height(&self) -> N {
-        num::cast::<f64, N>(2.0).unwrap() / self.mat.m22
+        <N as Cast<f64>>::from(2.0) / self.mat.m22
     }
 
     /// The near plane offset of the view cuboid.
@@ -187,14 +186,14 @@ impl<N: BaseFloat> OrthoMat3<N> {
     #[inline]
     pub fn set_width(&mut self, width: N) {
         assert!(!::is_zero(&width));
-        self.mat.m11 = num::cast::<f64, N>(2.0).unwrap() / width;
+        self.mat.m11 = <N as Cast<f64>>::from(2.0) / width;
     }
 
     /// Sets the height of the view cuboid.
     #[inline]
     pub fn set_height(&mut self, height: N) {
         assert!(!::is_zero(&height));
-        self.mat.m22 = num::cast::<f64, N>(2.0).unwrap() / height;
+        self.mat.m22 = <N as Cast<f64>>::from(2.0) / height;
     }
 
     /// Sets the near plane offset of the view cuboid.
@@ -215,7 +214,7 @@ impl<N: BaseFloat> OrthoMat3<N> {
     #[inline]
     pub fn set_znear_and_zfar(&mut self, znear: N, zfar: N) {
         assert!(!::is_zero(&(zfar - znear)));
-        self.mat.m33 = -num::cast::<f64, N>(2.0).unwrap() / (zfar - znear);
+        self.mat.m33 = -<N as Cast<f64>>::from(2.0) / (zfar - znear);
         self.mat.m34 = -(zfar + znear) / (zfar - znear);
     }
 
diff --git a/src/structs/quat.rs b/src/structs/quat.rs
index 509c42f1..c1fe1a00 100644
--- a/src/structs/quat.rs
+++ b/src/structs/quat.rs
@@ -3,7 +3,6 @@
 #![allow(missing_docs)] // we allow missing to avoid having to document the dispatch trait.
 
 use std::mem;
-use std::num;
 use std::slice::{Iter, IterMut};
 use std::ops::{Add, Sub, Mul, Div, Neg, Index, IndexMut};
 use std::iter::{FromIterator, IntoIterator};
@@ -176,7 +175,7 @@ impl<N: BaseFloat> UnitQuat<N> {
         }
         else {
             let ang    = sqang.sqrt();
-            let (s, c) = (ang / num::cast(2.0f64).unwrap()).sin_cos();
+            let (s, c) = (ang / Cast::from(2.0)).sin_cos();
 
             let s_ang = s / ang;
 
@@ -205,7 +204,7 @@ impl<N: BaseFloat> UnitQuat<N> {
     /// The primitive rotations are applied in order: 1 roll − 2 pitch − 3 yaw.
     #[inline]
     pub fn new_with_euler_angles(roll: N, pitch: N, yaw: N) -> UnitQuat<N> {
-        let _0_5: N  = num::cast(0.5f64).unwrap();
+        let _0_5: N  = Cast::from(0.5);
         let (sr, cr) = (roll * _0_5).sin_cos();
         let (sp, cp) = (pitch * _0_5).sin_cos();
         let (sy, cy) = (yaw * _0_5).sin_cos();
@@ -223,7 +222,7 @@ impl<N: BaseFloat> UnitQuat<N> {
 
     /// Builds a rotation matrix from this quaternion.
     pub fn to_rot(&self) -> Rot3<N> {
-        let _2: N = num::cast(2.0f64).unwrap();
+        let _2: N = Cast::from(2.0);
         let ww = self.q.w * self.q.w;
         let ii = self.q.i * self.q.i;
         let jj = self.q.j * self.q.j;
diff --git a/src/traits/structure.rs b/src/traits/structure.rs
index 93b0b4dd..fde314c1 100644
--- a/src/traits/structure.rs
+++ b/src/traits/structure.rs
@@ -16,7 +16,7 @@ pub trait BaseNum: Copy + Zero + One +
 }
 
 /// Basic floating-point number numeric trait.
-pub trait BaseFloat: Float + BaseNum {
+pub trait BaseFloat: Float + Cast<f64> + BaseNum {
     /// Archimedes' constant.
     fn pi() -> Self;
     /// 2.0 * pi.
@@ -387,7 +387,7 @@ macro_rules! impl_base_float(
 
             /// 2.0 * pi.
             fn two_pi() -> $n {
-                $n::consts::PI_2
+                2.0 * $n::consts::PI
             }
 
             /// pi / 2.0.